Autonomous machine for docking with a docking station and method for docking

ABSTRACT

An autonomous robot is designed for docking in a docking station. The autonomous robot is configured such that it will locate the docking station and dock therein, before its battery power is exhausted. The docking is such that the autonomous robot is automatically charged, such that its batteries will be fully powered for the subsequent operation.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 10/617,934, filed Jul. 11, 2003, the disclosure ofwhich is herein incorporated by reference.

TECHNICAL FIELD

The present invention is directed to autonomous machines, such asrobots, these robots typically designed to perform tasks such as vacuumcleaning, lawnmowing, floor sweeping and maintenance. In particular, thepresent invention is directed to methods and systems for docking theseautonomous machines in docking stations.

BACKGROUND

Autonomous machines and devices, such as autonomous robots, have beendesigned for performing various industrial and domestic functions. Thesedomestic functions include vacuum cleaning, lawn mowing, floor sweepingand maintenance. By extending robots to these domestic functions, theperson or user employing these robots has increased free or leisuretime, as they do not have to expend the time required to perform theaforementioned tasks manually.

These autonomous robots typically operate in accordance with variouscomputer programs that are part of the operating systems. Additionally,many of these autonomous robots are battery powered, and need to becharged once they are out of battery power. Additionally, if out ofbattery power, these autonomous robots typically stop where the powerran out and may be troublesome to locate or in difficult places toreach.

As a result, the autonomous robot must be located and manually broughtto the charging unit, typically an electrical outlet. These processesrequire the user taking the time to perform them. Additional time iswasted as the user typically must wait a few hours before the robot isrecharged, so it can start fresh again with fully charged batteries.

SUMMARY

The present invention improves on the contemporary art as it provides anautonomous robot, a docking station and a method for docking the robottherein. The autonomous robot is configured such that it will dock atthis docking station located at a known location, before its batterypower is exhausted. The docking is such that the autonomous robot isautomatically charged, such that its batteries will be fully powered forthe subsequent operation.

An embodiment of the invention is directed to an autonomous robot. Thisrobot has a system for moving it over a surface, a power system forproviding power to it, and including at least one sensor for detectingpower levels, and a control system in communication with the movingsystem, and the power system. The control system has a processor, forexample a microprocessor, programmed to: monitor the power level of thepower system; initiate a docking process for the robot to return to adocking station when the power level has fallen to a first apredetermined level; and continue the docking process by causing therobot to move toward the docking station. This robot can be used formultiple functions, for example, vacuum cleaning and lawn mowing.

Another embodiment of the invention is also directed to an autonomousrobot. This robot includes a system for moving the robot over a surface,at least one sensor (e.g., a receiver, typically an infrared (IR) lightreceiver) for detecting a signal from a docking station, a power systemfor providing power to the robot, the power system including at leastone sensor for detecting power levels; and a control system incommunication with the moving system, the at least one sensor fordetecting the docking station signal, and the power system. The controlsystem includes a processor, for example, a microprocessor, programmedto: monitor the power level of the power system; initiate a dockingprocess for the robot to return to a docking station when the powerlevel has fallen to or below a first predetermined level; and continuethe docking process. The processor is programmed to continue the dockingprocess by: receiving at least one signal from the at least one sensorthat a signal for a docking station has been detected; and responding tothe received at least one signal by causing the movement system to movethe robot toward the docking station. This robot can be used formultiple functions, for example, vacuum cleaning and lawn mowing.

Another embodiment is directed to a docking station for an autonomousrobot. The docking station has at least one transmitter for transmittinga docking beam, the docking beam including at least a first portion of afirst range and a second portion of a second range; and at least onecontact member configured for receiving a corresponding contact memberon a robot in a docking contact. The docking station also has a chargingsystem for transporting electricity to the robot when the dockingcontact is made.

Another embodiment is directed to a method for docking an autonomousrobot in a docking station. The autonomous robot that performs thismethod, also performs functions such as vacuum cleaning, lawn mowing,etc. This method includes monitoring battery voltage of the robot,initiating docking of the robot in the docking station when the batteryvoltage has been detected to have fallen to at least a firstpredetermined level, locating at least one signal for the dockingstation, and moving the robot toward the docking station. The locatingthe docking station signal and moving the robot toward the dockingstation continue while the battery voltage remains between the firstpredetermined level and a second predetermined level, the secondpredetermined level less than the first predetermined level. Should thebattery voltage fall to at least the second predetermined level, therobot will stop. This method also includes ceasing robot movement oncethe robot has docked in the docking station and a docking contactbetween the robot and the docking station is established. This dockingcontact is typically a physical contact as well as an electricalcontact, allowing electricity to be passed from the docking station tothe robot, for charging its battery or batteries when the robot is atrest and docked in the docking station. Additionally, the locating atleast one signal for the docking station includes two signal detections.First, the robot seeks and detects a signal from the docking station fora first time, and then detects the signal from the docking station for asecond time, typically confirming the location of the docking station.

Another embodiment of the invention is directed to a method for dockingan autonomous robot in a docking station. The autonomous robot thatperforms this method, also performs functions such as vacuum cleaning,lawn mowing, etc. This method includes monitoring battery voltage of therobot; initiating docking of the robot in the docking station when thebattery voltage has been detected to have fallen to at least a firstpredetermined level; locating at least one signal for the dockingstation and confirming that the at least one signal for the dockingstation has been located, and moving the robot toward the dockingstation. The locating and confirming the docking station signal andmoving the robot toward the docking station occur while the batteryvoltage remains between the first predetermined level and a secondpredetermined level, the second predetermined level less than the firstpredetermined level. Otherwise, should the battery voltage drop to atleast the second predetermined level, the robot ceases movement. Thismethod also includes ceasing robot movement once the robot has docked inthe docking station and a docking contact between the robot and thedocking station is established. This docking contact is typically aphysical contact as well as an electrical contact, allowing electricityto be passed from the docking station to the robot, for charging itsbattery or batteries when the robot is at rest and docked in the dockingstation.

BRIEF DESCRIPTION OF THE DRAWINGS

Attention is now directed to the drawing figures, where like numeralsand/or characters indicate corresponding or like components. In thedrawings:

FIG. 1 is a diagram of an apparatus in accordance with an embodiment ofthe invention;

FIG. 2 is a schematic diagram of the sensor and docking contactarrangement in the apparatus of FIG. 1;

FIGS. 3A and 3B form a flow diagram outlining a docking process inaccordance with an embodiment of the present invention;

FIGS. 4 and 5 are schematic diagrams detailing portions of the dockingprocess detailed in FIGS. 3A and 3B;

FIG. 6 is a flow diagram detailing homing of blocks 214/216 of FIGS.3A/3B;

FIG. 7 is schematic diagram detailing portions of the process detailedin FIG. 6;

FIG. 8 is a flow diagram detailing the contour movement of blocks218/220 of FIGS. 3A/3B;

FIG. 9 is a schematic diagram detailing portions of the process detailedin FIG. 8;

FIG. 10 is a flow diagram detailing the alignment phase of blocks222/224 of FIGS. 3A/3B;

FIG. 11 is a schematic diagram detailing portions of the processdetailed in FIG. 10;

FIG. 12 is a flow diagram detailing the end game or final docking phaseof blocks 226/228 of FIGS. 3A/3B;

FIG. 13 is a schematic diagram detailing the reacquire sequence (phase)of FIGS. 3A/3B; and

FIGS. 14-19 are state diagrams detailing an exemplary operation of theapparatus of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show an apparatus 20 or platform of the present invention,that is an autonomous machine or autonomous robot. The apparatus 20 issuch that it can be received by a docking station 100. In this dockingstation 100, the apparatus 20 will return to it once its task iscomplete, for orderly control and arrangement of the apparatus 20. Whilein this docking station 100, various functions can occur, such asbattery recharging and the like.

The apparatus 20 typically includes a body 22, supported by a chassis24, that supports various mechanical and electrical components, andsystems involving these components. The body 22 and chassis 24 ride onwheels 26, 28 rollers or the like, that with the related electronics,components and systems, as detailed below, as well as combinationsthereof, form a movement system for the apparatus 20 (for moving theapparatus 20 over a surface or the like).

There are at least two oppositely disposed wheels 26 at the sides of theapparatus 20, each driven by motors (M) 30 (independent of each other),to allow for steering of the apparatus 20. There is also typically onenon-motorized or passive wheel 28, typically at the rear of theapparatus 20, used to measure distance, direction and the like.

These motors (M) 30 are typically computer controlled, by a controlsystem 40, typically processor (microprocessor) based. The motorized 26and/or non-motorized 28 wheels may be part of a navigation system 42, adrive system 44, steering system 46, with the passive wheel 28 part of adistance measuring/odometry system 48. All of the aforementioned systemsare integrated and typically part of and controlled by the controlsystem 40, and allow for movement of the apparatus 20 as well asperforming the processes and methods detailed below.

The apparatus 20 is typically powered by batteries 50, typicallyrechargeable, that form part of a power system 52, that is electricallycoupled to the control system 40. Battery voltage sensors (BVS) 50 a,typically for each battery 50, are also part of the power system 52. Theforward and typical direction of movement for the apparatus 20 isindicated by the arrow 53.

The apparatus 20 also includes sensors, for example, for obstacledetection, obstruction detection, boundary detection, proximitydetection to objects and/or boundaries. These sensors form a sensorsystem 56, that is coupled to the control system 40 and are under thecontrol thereof.

The apparatus 20 also includes a payload 58, coupled to the controlsystem 40. This payload 58 can be designed for various tasks. Forexample, the payload can be a system suitable for vacuum cleaning, butcan also be designed for lawn mowing, surface cleaning, floor sweepingand the like.

Turning also to FIG. 2, The apparatus 20 includes front 62 a, 62 b,lateral 64 a, 64 b, and rear 66, receivers, that typically function assensors. These receivers 62 a, 62 b, 64 a, 64 b, 66 are exemplary, andmore and/or fewer receivers are also permissible. The receivers are forexample, infra-red (IR) light receivers and placed into the apparatus 20similar to the aforementioned sensors, and typically form part of thesensor system 56, that is coupled to the control system 40.

The apparatus 20 also includes docking contacts 68, typically at itsrear. These docking contacts 68 are typically metal or other magnetic orelectrically conducting materials. These docking contacts 68 areelectrically coupled to the control system 40, for example, through thepower system 52. Voltage sensors (DVS) 69, typically for each of thedocking contacts 68, and electrically coupled to the docking contacts 68and the control system 40, are also typically part of the power system52.

For example, one such autonomous machine or robot, suitable as theapparatus 20 here, including its components and systems, and operationaland work modes, including scanning patterns, is detailed in commonlyowned U.S. Patent Application Publication No. 20030060928 A1, entitled:Robotic Vacuum Cleaner, this document incorporated by reference herein.The apparatus 20 is also suitable for operational and/or work modes,including scanning patterns, such as those detailed in commonly ownedPCT International Application No. PCT/IL99/00248 (WO 99/59042), entitledArea Coverage With An Autonomous Robot, and U.S. Pat. No. 6,255,793,both of these documents incorporated by reference herein. While theapparatus 20 shown is a robotic vacuum cleaner, detailed above, anyautonomous machine, robot or the like, that performs functions includinglawn mowing, surface cleaning and the like, can be utilized.

The apparatus 20 can also be controlled at least partially by controlunits and controllers, such as those detailed in commonly owned U.S.Pat. Nos. 6,339,735 and 6,493,613, both patents entitled: Method ForOperating A Robot. Both of these patents are incorporated by referenceherein.

The docking station 100 includes docking contacts 110, that aretypically metal, or other magnetic or electrically conducting material,and are typically spring mounted on the docking station 100. Thesedocking contacts 110 are configured to correspond with the dockingcontacts 68 on the apparatus 20. Typically, these docking contacts 110have smooth surfaces, so as to contact the corresponding dockingcontacts 68 of the apparatus 20, when docking is achieved, and theapparatus 20 rests in the docking station 100.

Also within this docking station 100 is one or more transmitters 114.This transmitter(s) 114 is/are typically infra-red (IR) lighttransmitters. Transmissions from this transmitter 114 are for example,in the form of a docking beam 120, for example in the IR frequencyrange. This docking beam 120 is formed of overlapping ranges 121, 122.

The first range 121 is the short range (shown in slanted lines), wherecontinuous transmissions of a weak signal (weak beam), for example,approximately less then 50 cm, are emitted, for example, continuously,approximately 15 times per second. These transmissions are, for example,IR transmissions of a wavelength of approximately 920 nm at power levelsto be detected by the apparatus 20 approximately 50 cm or less away fromthe docking station 100. The second or long range 122 (shown in dots)transmissions include strong transmissions. For example, thesetransmissions include IR transmissions of approximately 920 nm, emittedat a power levels so as to be detectable by the apparatus at distancesof up to approximately 10 meters away from the docking station 100, andare made approximately 3-4 times a second.

FIGS. 3A and 3B are a flow diagram of a process for docking of theapparatus 20 in the docking station 100. This process is in hardware,software or combinations of both, and performed in the control system 40of the apparatus, typically by the microprocessor therein. Initially,battery voltage is monitored continuously, at block 202. This istypically done by any known monitoring program in the control system 40and/or microprocessor thereof, that is electrically coupled to batteryvoltage sensors 50 a (in the power system 52).

The movements of the apparatus 20 for docking are shown in FIGS. 4 and5, and will be described in conjunction with this flow diagram.

Docking is initiated when battery voltage has reached or dropped below apredetermined level (first predetermined level), at block 204. Forexample, the docking process will be initiated when the battery voltage,for example, as detected in the control system 40, through sensors(voltage sensors 50 a) in the power system 52, has dropped to or below(typically below) a predetermined or threshold voltage (a firstpredetermined or threshold voltage). For example, this predetermined orthreshold voltage is 19 volts, indicative of the batteries 50 needing tobe recharged.

If the battery voltage is above the predetermined or threshold voltage,the process returns to block 202. If the battery voltage is at or belowthe predetermined threshold, the process moves to block 206.

At block 206, the docking beam 120 from the docking station 100 issought by the apparatus 20. Turning to FIG. 4, the docking beam 120 fromthe docking station 100 is now sought by the apparatus 20. Here, theapparatus 20 performs a seek for the docking beam 120. This “seek”typically includes the apparatus 20 operating in accordance with arandom scan pattern, that is typically performed at a normal drive speed(and is illustrated, for example, by the pathway indicated by thepathway 126).

Throughout this “seek” process, there may be stopping events, at block208 and the battery voltage of the apparatus 20 is monitored, at block210, to see if it has fallen to or below (typically below) apredetermined or second threshold. These processes are contemporaneous,and their corresponding blocks in the flow diagram can be reversed.

The stopping event at block 208, can occur if the bumper/wheels arestuck or if a stair has been detected, or other unexpected event, thatis considered inadequate for further pursuing the beam location or wouldnot allow the apparatus 20 to move in a straight course to the dockingstation 100. If a stopping event has occurred, the process returns toblock 206.

Battery voltage is monitored, at block 210. If the voltage has droppedat least to or below (and typically below) this second threshold, forexample, 16 volts, the process moves to block 211, where the apparatuscontrol system 40 signals the apparatus 20 to stop. This stoppage in atthe present location of the apparatus 20. The stoppage is such thatbattery power has been exhausted to a level where a further batterydischarge is not permissible and/or adequate operation of the apparatus20 itself is no longer possible, then the apparatus 20 stops and shutsitself down completely to achieve a minimal level of power consumption.

If the battery voltage (as detected by the voltage sensors 50 a andsignaled to the control system 40) is above this second predeterminedvoltage, the process continues (from block 210) to block 212. The “seek”terminates when the docking beam 120, typically a strong docking beam122, has been “seen”, at block 212, so as to be detected by the at leastone of the sensors 62 a, 62 b, 64 a, 64 b and 66, and subsequentlylocated so as to be “registered” in the control system 40 of theapparatus 20.

During this “seek”, the random scan pattern for the apparatus 20 ismodified in the control system 40. For example, thresholds for stoppingare relaxed such that the apparatus 20 will remain clear of obstaclesand stop further away from them, than when in a normal cleaning or workmode (as detailed above).

However, should the docking beam 120 have been detected, but not locatedat block 212, the process returns to block 206.

With the docking beam now located, The process now moves to block 214,where homing is performed. Homing is typically in three sequences, beamconfirmation, return, and repositioning. All three of these events aresubject to stopping events, collectively referred to at block 216, thatif one such stopping event occurs, the process returns to block 206.

Homing is detailed in the flow diagram of FIG. 6 and the diagram of FIG.7, to which attention is now directed.

Initially, homing starts at block 302, as the docking beam has beenlocated (at block 212 above). The first portion of homing, beamconfirmation, is in block 303. This block includes the subprocesses ofthe apparatus 20 performing a 180 degree turn in the direction fromwhich the beam 120 was detected, as indicated by the arrow 150, at block304. This 180 degree turn is in the direction the beam is most likelycoming from, as determined by the sensor through which it was detected.A second rotation is then made, at block 306, typically placing thefront end of the apparatus 20 in a substantially straight line with thesource of the docking beam 120, by moving the apparatus 20 in thedirection the beam is most likely coming from. This movement is inaccordance with an estimation algorithm in the control system 40, forexample, turning the apparatus 20 to the median angle of all of theangles from which an IR beam was received during the aforementioned180-degree turn.

It is then determined if the beam 120 is detected again and registeredor “seen”, at block 308. If no, there is only the initial registrationand this is considered to be a reflection. The process returns to block206.

If the beam 120 has been “seen” at block 308, the process moves to block310, where the presence of a stopping event is determined. Here, astopping event occurs if the bumper/wheels are stuck or if a stair hasbeen detected, or other unexpected event that is considered inadequatefor further pursuing the beam location or would not allow the apparatus20 to move in a straight course to the docking station 100. If astopping event has occurred, the process returns to block 206.

If a stopping event has not occurred, the process proceeds to the returnsequence, at block 312. Here, the apparatus 20 drives toward the source114 of the beam 120 (for example, a beam transmitter) as indicated bythe arrow 154. This movement toward the beam source continues until theapparatus 20 is approximately 60 cm from the beam transmitter 114 (FIG.5), as determined by a proximity sensor (not shown) electrically coupledto the control system 40.

It is then determined if there is a stopping event, at block 314. Ifthere is a stopping event, this return sequence stops, and the processreturns to block 206. Stopping events occur if the bumper/wheels arestuck or a stair has been detected (as detailed for block 310 above).

If a stopping event has not occurred, the process proceeds to therepositioning sequence, at block 317. At block 318, the apparatus 20moves toward an obstacle or object, for example, a wall 156. Initially,the apparatus 20 turns to the right and drives in a curved movement, asindicated by the arrow 158, toward the expected location of a wall 156.The apparatus 20 stops approximately 1 meter to the right of the dockingstation 100, at or proximate a location 159. However, if an obstacle isdetected, at block 320, the apparatus 20 will stop and start a wallfollowing procedure around it, at block 322, assuming it is part of theroom's perimeter geometry, meaning a contour on its right side(wall-following around this obstacle). This wall following willeventually lead the apparatus 20 to the wall 156, where the dockingstation 100 is positioned.

It is then determined if there is a stopping event, at block 324, fromblocks 310 and 314. If there is a stopping event, the process returns toblock 206. Stopping events occur if the bumper/wheels are stuck or astair has been detected (as detailed for blocks 310 and 314 above).

If a stopping event of blocks 310, 314, 324, represented generally atblock 216, has not occurred, the process moves to block 218, where acontour movement or wall following occurs. This contour movementterminates due to stopping events, collectively indicated at block 220.This contour movement of block 218 and stopping event of block 220 aredescribed in detail in the flow diagram of FIG. 8 and FIG. 9, bothfigures to where attention is now directed.

Initially, at block 340, the apparatus 20 follows the contour of theobject or obstacle, typically a wall 156. Here, the apparatus 20 (at thelocation 159) turns toward the docking station 100, as represented bythe arrow 160, and follows the contour of the object to its right (asdetailed above). Here, for example, the apparatus 20 follows the wall156 (as detailed above). This following is in the path represented bythe arrow 162 until one of the receivers 62 a, 62 b, 64 a, 64 b, 66detects the signal, strong or weak, from the docking contacts 110, forexample, here at a location 164.

Detection of the docking beam 120, by the apparatus 20 is noted, atblock 342. If the docking beam 120 has not been detected, the processreturns to block 340. If the docking beam 120 has been detected, it isthen determined if there is an obstacle, at block 344. If an obstaclehas been detected, the process returns to block 340. If an obstacle hasnot been detected, the process continues at block 346, where it isdetermined if there is a stopping event.

The stopping event can be that the bumper/wheels are stuck or a stairhas been detected (as detailed for blocks 310, 314 and 324 above). Ifthere is a stopping event, the process returns to block 206. If there isnot a stopping event, the process moves to block 208.

While blocks 342, 344 and 346 have been shown in an order here, this isexemplary only, as the sub-processes of these blocks are performedcontemporaneous with respect to each other. Any order for these blocksis suitable.

At block 348, it is determined if the docking station 100 has been foundby the apparatus 20. If the docking station 100 has been found, theapparatus 20 stops, at block 350, at a position proximate the dockingstation 100, as shown in FIG. 9. The process now moves to an alignmentphase, at block 222.

If the docking station 100 was not found, it is determined (by anodometer or other distance measuring device in the apparatus 20) if theapparatus 20 has traveled more than 3 meters without finding the dockingstation 100, at block 352. If travel has not exceeded this approximatelythree meters, the process returns to block 340. If this approximatelythree meter distance has been exceeded, the process returns to block206.

The apparatus 20 will now begin the alignment phase, at block 222.During this alignment phase, the apparatus 20 positions itself to be inalignment with the docking station 100. The alignment is such that ifsuccessful, the presence of a contact between the docking contacts 68 onthe apparatus 20 and those 110 on the docking station 100 is detected,at block 224. If no contact is detected from any of the alignmentprocedures, the process moves to a reacquire phase, at block 240. If acontact is established, the process moves to block 226, where the endgame for docking occurs.

The alignment phase of blocks 222 and 224 will now be described indetail, based on the flow diagram of FIG. 10, and FIG. 11.

Alignment begins at block 400 where the apparatus 20 performs a 90degree turn (from location 164 of FIG. 8), the first sequence ofdocking. Specifically, the apparatus 20 rotates approximately 90 degreesto the left, such that its docking contacts 68 align with the dockingcontacts 110 of the docking station 100.

Next, at block 402, a reverse sequence is performed. Here, the apparatus20 performs a short reverse movement, typically moving about 6 cm (tolocation 166), during which it is determined if there is a dockingcontact, at block 404, between the apparatus 20 and the docking station100. This is typically determined through voltage measurements (asdetected by the voltage sensors 69) on the docking contacts 68 on theapparatus 20 (as detailed above). For example, voltages suitable to fora sufficient “contact” in block 404 can be any predetermined positivevoltage, typically approximately 20 volts or less. If there is acontact, the process moves to the end game or docking phase, at block226 (FIG. 3A/3B).

If there is not a contact, the apparatus 20 stops, at block 406. Awiggle sequence, at block 408, is now performed. In this wigglesequence, the apparatus 20, travels from an initial location 166,proximate to the docking contacts 110, to a new location 170, where itperforms a short, approximately five degree, turn to the left, andtraveling to a location 172, where a reverse movement is preformed. Thisreverse movement, for example, approximately 1 cm or less, terminates atthe point 174.

At block 410, it is determined if the wiggle sequence resulted in acontact, as per block 404. If a contact is detected, the process movesto the end game at block 226. If a contact was not detected, the processmoves to block 412, where it is determined if a predetermined number ofwiggle sequences have been performed. This predetermined number is, forexample, four. Accordingly, should the number of wiggle sequencesattempted be four or less, the process returns to block 408, where asubsequent wiggle sequence is performed. Alternately, if the requisitenumber of wiggle sequences has been performed (for example, four here),the process moves to block 240, where a reacquire phase or sequence isperformed. In this alignment phase, the contacts described at blocks 404and 410 are collectively block 224 of FIGS. 3A/3B.

The process is now at the end game or docking phase, block 226. The endgame results in the presence or non-presence of docking contact (betweendocking contacts 110 of the docking station 100 and correspondingdocking contacts 68 of the apparatus 20), block 228. If successful, thedocking contact is detected by the control system 40 (via the voltagesensors 69, as detailed above) as the voltage on the docking contacts 68has reached a predetermined level, for example, approximately 20 or morevolts (as detailed below), rendering the process complete. The processends at block 230, as the apparatus 20 stops and its power system 52,for example its batteries 50 are charged (as electricity is beingtransmitted throughout the docking station 100 through the contacts 68to the power system 52). If unsuccessful, the process returns to thereacquire phase, of block 240.

Blocks 226-230 for the end game are now described in detail, in the flowchart of FIG. 12.

Initially, once a contact, between docking contacts 110 of the dockingstation 100 and docking contacts 68 of the apparatus 20, is detected bythe control system 40 (through voltage sensors 69 in the power system52) of the apparatus 20 (at block 224, and equivalent blocks 404 and410), the apparatus 20 stops, at block 430. This stop is for a period ofapproximately 2 seconds, and is done to account for the spring-likebehavior of the docking station 100, the possibility of a slippery floorsurface or a thick carpet surface, as well as any potential small joltsthat apparatus 20 experiences when coming to a full stop in the dockingstation 100. With the stop or rest period expired, the voltage on thedocking contacts 68 of the apparatus 20 is measured, at block 432.

If a rise in the voltage is present, such as a rise in voltage to atleast a predetermined voltage level, for example, approximately 20volts, as sensed by the voltage sensors 69 electrically coupled to thedocking contacts 68 (as detailed above), a docking contact (between thedocking contacts 68 of the apparatus 20 and the docking contacts 110 ofthe docking station 100) is present, and the process moves to block 230.With an established docking contact (for example, at or above thepredetermined level, here, 20 or more volts), the process is complete,as the apparatus 20 is charging (as detailed above). If a voltage wasdetected below the predetermined level, for example, approximately 20volts, as detailed above, a momentary contact was made between thedocking contacts 68, 110, of the apparatus 20 and docking station 100,respectively, but these contacts are no longer present after the stopperiod. As a result, a reverse movement is initiated, at block 434, inan attempt to reestablish the contact.

This reverse movement, at block 434, is, for example, a short movement,of approximately 1 cm. With this reverse movement complete, the voltageon the docking contacts 68 of the apparatus 20 is again measured, atblock 436. This measurement is in accordance with that described forblock 432 above.

If a rise in the voltage, for example, to the predetermined level ofapproximately 20 or more volts, as detailed above, a docking contact (asdetailed above) is present, and the process moves to block 230, where itis complete, as the apparatus 20 is charging (as detailed above). If norise in voltage has been detected, for example, a momentary contact wasmade between the docking contacts 68, 110, but the contacts 68 of theapparatus 20 are not touching or are not coupled with the contacts 110of the docking station 100, it is then determined if a predeterminednumber of reverses have been made, at block 438. This predeterminednumber of reverses is for example, two. If two or fewer reverses havebeen made, the process returns to block 434. If two reverses have beenmade, the process moves to the reacquire phase of block 240.

Turning also to FIG. 13 and back to FIGS. 3A/3B, this reacquire phase orsequence, of block 240 is shown. The apparatus 20, for example, is atpoint 186, proximate to the docking station 100. A movement is now madein a direction away from the docking station 100, in the direction ofthe arrow 188. The movement then continues with a curved portion 190,ending in a position proximate to the wall 156, and a predetermineddistance, for example, approximately 1 meter, from the docking station100.

At this point, it is determined if this attempt at the reacquire phaseis within a predetermined number of attempts, for example, typicallyfour, at block 242. If this is the fourth or less attempt at thereacquire phase (of block 240), the process returns to block 218, wherethe contour movement resumes (and the apparatus will move along the wall156 as indicated by the arrow 192). Otherwise, if four attempts havebeen made at the reacquire phase, the process terminates at block 210.Here, the docking procedure has failed and the apparatus 20 will shutdown, typically to a power conserving mode, with no further dockingattempts performed.

EXAMPLE

FIGS. 14-19 are state diagrams detailing an operative example of adocking process, in accordance with FIGS. 1-13 shown and describedabove. While these state diagrams are for the apparatus 20, detailedabove, other autonomous robots, machines or the like can also beoperated in accordance with these exemplary state diagrams. FIG. 14shows the entire docking process, while FIGS. 15-19 detail portions ofthe process listed in FIG. 14.

The processes (methods) (including sub-processes) and systems (includingcomponents) described herein have been described with exemplaryreference to specific hardware and/or software. These methods have beendescribed as exemplary, whereby specific steps and their order can beomitted, and/or changed by persons of ordinary skill in the art toreduce embodiments of the above disclosed processes and systems topractice without undue experimentation. The processes and systems havebeen described in a manner sufficient to enable persons of ordinaryskill in the art to readily adapt other commercially available hardwareand/or software as may be needed to reduce any of the above disclosedembodiments to practice.

Thus, there has been shown and described an apparatus, method and systemfor docking an autonomous robot or machine, which fulfills all theobjects and advantages sought therefor. It is apparent to those skilledin the art, however, that many changes, variations, modifications, andother uses and applications for the apparatus, method and system ofdocking and resultant media are possible, and also such changes,variations, modifications, and other uses and applications, which do notdepart from the spirit and scope of the invention are deemed to becovered by the invention, which is limited only by the claims whichfollow.

1. An autonomous robot comprising: a movement system for moving therobot over a surface; a power system for providing power to the robot,the power system including at least one sensor for detecting powerlevels; at least one sensor for detecting at least one signal from adocking station; and a control system in communication with the movementsystem, the power system, and the at least one sensor, the controlsystem including a processor programmed to: monitor the power level ofthe power system; initiate a docking process for the robot to return tothe docking station when the power level has fallen to a first apredetermined level; cause the movement system to move the robot for theat least one sensor to detect the at least one signal from the dockingstation.
 2. The robot of claim 1, wherein the processor is additionallyprogrammed to: continue the docking process until the power level hasfallen to a second predetermined level, the second predetermined levelbeing less than the first predetermined level.
 3. The robot of claim 2,wherein the processor programmed to continue the docking processincludes: causing the robot to move into contact with the dockingstation.
 4. The robot of claim 2, wherein the processor is additionallyprogrammed to cause the robot to stop if the power level has fallen toat least the second predetermined level.
 5. The robot of claim 1,wherein the at least one sensor for detecting at least one signal fromthe docking station is configured for detecting a docking beam, from thedocking station.
 6. The robot of claim 5, wherein the processor isadditionally programmed to: receive a first signal from the at least onesensor that docking beam has been detected and receiving a second signalfrom the at least one sensor confirming the detection of the dockingbeam.
 7. The robot of claim 6, wherein the at least one sensor includesa plurality of sensors.
 8. The robot of claim 7, wherein the pluralityof sensors include infrared light receivers.
 9. The robot of claim 1,additionally comprising: at least one electrical contact incommunication with the power system and the control system forcontacting at least one corresponding contact on a docking station andreceiving electricity therethrough for charging the power system. 10.The robot of claim 9, wherein the power system includes at least onebattery.
 11. The robot of claim 4, wherein the processor programmed tocontinue the docking process includes: causing the robot to move towardan obstacle.
 12. The robot of claim 11, wherein the processor programmedto continue the docking process includes: causing the robot to movealong the obstacle to a point proximate the docking station.
 13. Therobot of claim 12, wherein the processor programmed to continue thedocking process includes: causing the robot to perform at least onewiggle movement toward the docking station.
 14. The robot of claim 3,wherein the processor programmed to continue the docking process isadditionally programmed to: cause the docking process to terminate andcease movement of the robot when a signal corresponding to a dockingcontact with a docking station is made.
 15. The robot of claim 1,wherein the processor programmed to monitor the power level of the powersystem includes monitoring battery voltage.
 16. The robot of claim 1,configured for vacuum cleaning.
 17. The robot of claim 1, configured forlawn mowing.
 18. A docking station for an autonomous robot comprising:at least one transmitter for transmitting a docking signal, the dockingsignal including at least a first portion of a first range and a secondportion of a second range; and at least one contact member configuredfor receiving a corresponding contact member on a robot in a dockingcontact.
 19. The docking station of claim 18, additionally comprising: acharging system for transporting electricity to the robot when thedocking contact is made.
 20. The docking station of claim 18, whereinthe first range is a short range transmission.
 21. The docking stationof claim 18, wherein the second range is a long range transmission. 22.An autonomous robot comprising: a movement system for moving the robotover a surface; at least one sensor for detecting a signal for a dockingstation; a power system for providing power to the robot, the powersystem including at least one sensor for detecting power levels; and acontrol system in communication with the movement system, the at leastone sensor for detecting the docking station signal, and the powersystem, the control system including a processor programmed to: monitorthe power level of the power system; initiate a docking process for therobot to return to a docking station when the power level has fallen toa first a predetermined level; and continue the docking processincluding: receiving at least one signal from the at least one sensorthat a signal for a docking station has been detected; and responding tothe received at least one signal by causing the movement system to movethe robot toward the docking station.
 23. The robot of claim 22, whereinthe processor programmed to continue the docking process includes:operating the robot until the power level has fallen to a secondpredetermined level, the second predetermined level being less than thefirst predetermined level.
 24. The robot of claim 22, wherein theprocessor programmed to continue the docking process includes: causingthe robot to move into contact with the docking station.
 25. The robotof claim 23, wherein the processor is additionally programmed to causethe robot to stop if the power level has fallen to at least the secondpredetermined level.
 26. The robot of claim 22, wherein the receiving atleast one signal includes: receiving a first signal from the at leastone sensor that a signal for a docking station has been detected, andreceiving a second signal from the at least one sensor confirming thedetection of the signal for the docking station.
 27. The robot of claim22, additionally comprising: at least one electrical contact incommunication with the power system and the control system forcontacting at least one corresponding contact on a docking station andreceiving electricity therethrough for charging the power system. 28.The robot of claim 22, wherein the power system includes at least onebattery.
 29. The robot of claim 23, wherein the processor programmed tocontinue the docking process includes: causing the movement system ofrobot to move toward an obstacle.
 30. The robot of claim 29, wherein theprocessor programmed to continue the docking process includes: causingthe robot to move along the obstacle to a point proximate the dockingstation.
 31. The robot of claim 30, wherein the processor programmed tocontinue the docking process includes: causing the robot to perform atleast one wiggle movement toward the docking station.
 32. The robot ofclaim 24, wherein the processor programmed to continue the dockingprocess includes: causing the docking process to terminate and ceasemovement of the robot when a signal corresponding to a docking contactwith a docking station is made.
 33. The robot of claim 22, wherein theprocessor programmed to monitor the power level of the power systemincludes monitoring battery voltage.
 34. The robot of claim 22,configured for vacuum cleaning.
 35. The robot of claim 22, configuredfor lawn mowing.
 36. The robot of claim 22, wherein the at least onesensor includes a plurality of sensors.
 37. The robot of claim 36,wherein the plurality of sensors include infrared light receivers.